Speaking at the MacGill Summer School, the former tanaiste and justice minister said: "Very welcome as Frances Fitzgerald's appointment is, the circumstances that led to it still are murky as far as most of us are concerned."

He said that the failure of the Taoiseach to offer an explanation to the Dail was "an abdication from one of the cornerstones of our democratic system".

He added: "Our Dail was confronted with obfuscation and a deliberate pattern of not answering the questions straight."

Mr Shatter resigned on May 7 following the publication of the Guerin Report into garda whistleblowers. His resignation was preceded by that of garda commissioner Martin Callinan in March, the day after the Taoiseach sent the secretary general of the Justice Department Brian Purcell to his house.

Mr McDowell SC also criticised the Government's planned reforms to An Garda Siochana, saying that control of the the force should remain in the hands of the Government. He also criticised planned garda reforms and questioned the wisdom of removing oversight of the gardai from the Government and giving it to an independent policing authority, comparing such a body to the HSE or the RTE board.

McDowell said such a situation would allow the Government to distance itself from any blame when things go wrong in the force. "I don't believe it's a good idea for that State to divest itself of responsibility and distance themselves from blame," he said.

During a question-and-answer session, Mr McDowell also said that "there is a disease in An Garda Siochana . . . of indifference and cynicism", though he added that the "great majority" of the force did not suffer from the disease.

He said he was "sickened" by the abuse of the garda disciplinary system which in some cases saw guards "being hammered for tiny things" but bigger issues were let go.

Responding, Justice Minister Frances Fitzgerald said that Mr McDowell's concerns were relevant and that he raised "serious questions" that would be examined in drafting the reforms.

Complex

"As Justice Minister I do want to see confidence trumping controversy," she said, adding that the setting up of a new garda authority is "complex – we have to develop our own model".

Addressing the law and justice panel last night, Ms Fitzgerald called for a comprehensive overhaul of how gardai tackle what she described as the "bread-and-butter" issues in every district in the State.

She said Justice reform demanded that they move beyond the "big ticket" specific changes and confront the complex and deep-rooted issues that affected everybody.

Ms Fitzgerald was expanding on her hard-hitting comments in yesterday's Irish Independent, where she said the public image of the force had been tainted by massive controversy and public mistrust.

Those remarks drew a sharp response last night from Garda middle management, who said the Government must also take its share of the responsibility.

John Redmond, general secretary of the Association of Garda Sergeants and Inspectors, said the workload on his members had increased while the Government cut their pay and also slashed the strength of the force.

He believed gardai were prepared to implement the necessary changes but pointed out that they had to be fully involved from the start in a partnership approach.